JP3133041B2 - Method for producing fiber-reinforced thermosetting resin molded product - Google Patents

Description

The present invention relates to a method for producing a fiber-reinforced thermosetting resin molded product.

The method for producing a fiber-reinforced thermosetting resin molded product of the present invention is,
It can be used in fields that require large-sized molding, such as the automotive industry and construction.

[Conventional technology]

Conventionally, as means for molding a fiber-reinforced thermosetting resin, there are hand lay-up molding, press molding, pultrusion molding, filament winding molding, resin transfer molding and the like. When molding large molded products, hand lay-up molding has the advantage of low mold cost and no capital investment.However, because the molding cycle is long and the glass mats are laminated by hand, the glass mats have the problem of springback of the glass mats. It is difficult to increase the content. In press molding, although the molding cycle is short, a sheet-like compound (SM
High pressure is required to press C) or bulk compound (BMC), and the larger the product to be obtained, the higher the capital investment in the press and the mold. Further, there is a problem that the shape of the molded product is greatly restricted in the drawing molding and the filament winding molding. Among these, resin transfer molding is most suitable for large-sized molding. In addition, using a reaction injection molding machine (RIM machine) used in the urethane field, Structural-RIM (RIM machine) is used to increase the strength by reacting two liquids that are reactive with each other into a mold filled with a reinforcing material in advance. There is also a molding method called S-RIM) molding, and this molding method can be said to be a broad category of resin transfer molding, judging from the molding process. The difference between conventional resin transfer molding and S-RIM molding lies in the difference in the injection machine. In the case of resin transfer molding, since the injection machine is a constant-pressure injection machine, the injection time changes when the back pressure generated at the time of injection changes depending on the degree of filling of the glass fiber in the mold. Therefore, when the glass content is increased to obtain a high-strength molded product, the pouring time is considerably long, but the gelling time can be arbitrarily changed by a slow reaction rate, such as an ordinary unsaturated polyester resin, by using an inhibitor and a catalyst system. Things don't matter. However, in a resin system in which an unsaturated polyester resin is reacted with a polyisocyanate compound to obtain a molded article having higher strength and high elasticity, a urethane-forming reaction with a high reaction rate is involved, so that a long time is required for injection. If necessary, the reaction proceeds during the injection, causing a significant increase in the viscosity, and the injection cannot be performed. Therefore, in such a resin system, it is necessary to inject the resin for a certain period of time irrespective of the degree of back pressure in the mold, and also for a short period of time. Since the RIM machine is a constant speed (flow rate) injector, it is suitable for a fast reaction system in which the injection time does not fluctuate due to the influence of the back pressure. However, even in this case, when injected into a mold filled with glass fiber at a high speed, a considerably high back pressure is generated, the machine stops due to exceeding the pump capacity, or a RIM machine's metering mixer (mixing head) Liquid may leak from the mounting portion between the mold and the mold. In order to form a molded article having a high glass content in order to increase the strength as described above, the back pressure generated in both the resin transfer molding and the S-RIM molding becomes a problem. That is, to perform molding in a short time, lower this back pressure and inject resin smoothly,
It is necessary that the reaction is completed immediately after filling the resin and the resin is cured. Therefore, it is particularly important to reduce the viscosity of the resin and to suppress the increase in viscosity (initial thickening) due to the reaction during the injection to a low level. However, there is no resin system that meets such conditions so far.

[Problems to be solved by the invention]

The present inventors have conducted intensive studies on a resin system in which the viscosity of the resin and the viscosity increase (initial thickening) due to the reaction during the injection are suppressed, and the reaction is completed promptly after the injection and leads to curing. Reached.

[Means for solving the problem]

That is, the present invention relates to a fiber in which a raw material component containing an active hydrogen compound (A) and a polymerizable vinyl monomer (B) and a raw material component containing a polyisocyanate compound (C) are reaction injection molded into a fiber (D). In the method for producing a reinforced thermosetting resin molded product, (A) is an unsaturated dicarboxylic acid or an acid anhydride thereof.
Unsaturated polyester having a hydroxyl value of 110 to 280 mgKOH / g and an acid value of 5 mgKOH / g or less obtained from a dicarboxylic acid or an acid anhydride thereof containing 40 to 100 mol% and a polyhydric alcohol having a primary hydroxyl group ( to a _1), an epoxy equivalent of having at least one epoxy group in the molecule
Selected from the group consisting of unsaturated epoxy esters (a ₂ ) obtained from 70 to 200 epoxy compounds and a polymerizable unsaturated monobasic acid, and acrylic compounds (a ₃ ) having an acryloyl group and a hydroxyl group in the molecule. An active hydrogen compound comprising at least one compound, wherein the ratio of a ₁ , a ₂ , and a ₃ is (a ₂ + a ₃ ) / (a ₁ + a ₂ + a ₃ ) × 100 = 1 to 15 wt%. (B) is a polymerizable vinyl monomer containing 5 to 40% by weight, preferably 10 to 25% by weight of methyl methacrylate; A liquid polyisocyanate compound having a viscosity at 25 ° C. of 10 to 200 cps, and the following conditions (i) and (ii):
(Iii) (i) (B) is 20 to 50 with respect to the total amount of (A) and (B).
wt% is (ii) the isocyanate group of (C) is 0.75 to 1.2 times the hydroxyl group of (A), and (iii) (D) is (A), (B), (C) and (D) A method for producing a fiber-reinforced thermosetting resin molded product, which satisfies 30 to 75 wt% with respect to the total amount.

The unsaturated polyester (a ₁ ) used in the present invention contains 40 to 10 unsaturated dicarboxylic acids or acid anhydrides as an acid component.
A mixture of 0 mol% and a saturated dicarboxylic acid or 60 mol% or less of an acid anhydride thereof is used. A polyhydric alcohol having a primary hydroxyl group is used as an alcohol component, and these are subjected to a dehydration condensation reaction by a method known per se. Polycondensate. The unsaturated polyester used in the compositions of the present invention (a ₁₎ has a hydroxyl number acid value is less than or equal 5 mgKOH / g is in the range of 110~280mgKOH / g. Acid number 5
A fiber-reinforced thermosetting resin molded product produced using an unsaturated polyester exceeding mgKOH / g easily foams at the time of molding and causes a decrease in strength. Hydroxyl value is 110mgKOH / g
If it is less than ₁ , the molecular weight of the unsaturated polyester (a ₁ ) will be greater than 1000 (by the end-group method), resulting in reduced impregnation of the glass fibers and a hydroxyl number of 280 m
When it is larger than gKOH / g, the molecular weight of the unsaturated polyester is smaller than 500 (by the end group method), so that the impregnation into the glass fiber is good but the impact resistance is insufficient. Here, unsaturated dicarboxylic acids or acid anhydrides thereof include, for example, maleic acid, maleic anhydride and fumaric acid, and saturated dicarboxylic acids or acid anhydrides thereof include, for example, phthalic acid, phthalic anhydride and isophthalic acid. , Terephthalic acid, heptic acid, and polyester resins are conventionally treated as saturated acids. Examples thereof include tetrahydrophthalic anhydride. Examples of the polyhydric alcohol having a primary hydroxyl group include ethylene glycol, diethylene glycol, 1,4-butanediol, and neopentyl glycol. Polyhydric alcohols containing a secondary hydroxyl group, such as propylene glycol, dipropylene glycol, and bisphenol A-propylene oxide adducts, can also be used in combination, but are preferably 5 mol% or less. When an unsaturated polyester produced using 5 mol% or more of a polyhydric alcohol containing a secondary hydroxyl group is used, only a composition having low impact resistance can be obtained. The unsaturated polyester (a ₁ ) of the present invention includes:
Conventional polymerization inhibitors such as hydroquinone, parabenzoquinone, methylhydroquinone and the like can be used.

The unsaturated epoxy ester (a ₂ ) used in the present invention is obtained from an epoxy compound having an epoxy equivalent of 70 to 200 having at least one epoxy group in a molecule and a polymerizable unsaturated monobasic acid. is there. In the present invention, when an unsaturated epoxy ester obtained from an epoxy compound having an epoxy equivalent greater than 200 and a polymerizable unsaturated monobasic acid is used, the viscosity of the resin intended for the present invention and the viscosity increase due to a reaction during injection are increased. (Initial thickening) cannot be suppressed. Examples of the unsaturated epoxy ester (a ₂ ) include a vinyl ester resin obtained from bisphenol type epoxy and novolak type epoxy.

The acrylic compound (a ₃ ) has an acryloyl group and a hydroxy group in the molecule, and examples of the acrylic compound include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. Is raised.

Further, the mixing ratio of these is (a ₂ + a ₃ ) / (a ₁ + a ₂ + a ₃ ) × 100 = 1 to 15 wt%. When a large molded product is molded, it becomes difficult to secure an injection time.

Examples of the polymerizable vinyl monomer (B) that can be mixed with the unsaturated polyester include styrene, chlorostyrene, vinyl toluene, (meth) acrylic acid, and derivatives thereof.

In preparing the active hydrogen compound (A) and the polymerizable vinyl monomer (B) by the method of the present invention, the amount of the active hydrogen compound is in the range of 50 to 80% by weight, and the amount of the polymerizable vinyl monomer is 20%.
It can be used in the range of 5050% by weight. The polymerizable vinyl monomer contains methyl methacrylate in an amount of 5 to 40% by weight, preferably 10 to 25% by weight. If the proportion of methyl methacrylate exceeds 40% by weight, the curing time becomes longer. When the proportion of methyl methacrylate is less than 5% by weight, it is impossible to suppress the increase in viscosity (initial thickening) due to the reaction of the resin and the reaction during the injection, which is the object of the present invention.

The polyisocyanate compound (C) that can be used in the composition of the present invention has a terminal group And a viscosity at 25 ° C. of 10 to 2000 cps, preferably 3
A liquid polyisocyanate compound having a viscosity of 0 to 1500 cps, that is, a liquid diphenylmethane diisocyanate (for example, Is
compound commercially available under the trade name onate 143L), 4,
Polyether prepolymers of 4-diphenylmethane diisocyanate (e.g., a compound commercially available under the trade name Isonate 181), polyester prepolymers of 4,4'-diphenylmethane diisocyanate (e.g., Is
compound commercially available under the trade name onate 240). The amount of the polyisocyanate compound (C) to be used is limited to the range of 0.75 to 1.20 mole times the isocyanate group with respect to the hydroxyl group of the active hydrogen compound (A).

The fiber (D) is preferably glass fiber, carbon fiber, or aramid fiber in consideration of strength, affinity with resin, price, and the like, and glass fiber is particularly preferable.

The resin used in the present invention can be used in the following manner to obtain a fiber-reinforced thermosetting resin molded product. On the polyol side of the RIM machine, the active hydrogen compound (A) and the polymerizable vinyl monomer (B) are combined with a conventional curing accelerator such as dimethylaniline and cobalt naphthenate, and cobalt octenoate and di-laurate di-n. A conventional urethanizing catalyst such as butyltin is added and used. Also RIM
The polyisocyanate compound (C), t-butyl perbenzoate, t-
A conventional curing catalyst having no active hydrogen, such as butyl peroctoate or benzoyl peroxide, is added for use. The mold is filled with fiber (D),
Using the RIM machine prepared as described above, a two-component resin is uniformly mixed and injected into a mold to allow a urethanization reaction and a radical reaction to be performed almost simultaneously, thereby obtaining a fiber-reinforced thermosetting resin molded product. it can.

〔The invention's effect〕

In the present invention, specific components (A), (B), (C),
By mixing (D) in a specific ratio, a low viscosity after mixing, a relatively slow initial thickening and a curing reaction in a short time can be obtained, and a large fiber reinforced thermosetting by S-RIM molding. A resin molded product can be obtained.

〔Example〕

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to only these examples.

Synthesis Example 1 Synthesis of Unsaturated Polyester and Preparation of Unsaturated Polyester Resin (A) Isophthalic acid 1034 was placed in a reactor equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a partial reflux unit equipped with a thermometer in the tower.
g, neopentyl glycol 1687g, ethylene glycol
1006 g was charged, heated while flowing nitrogen gas, heated to 200 ° C., and a dehydration condensation reaction was performed according to a conventional method. Steam at 100 ° C. was passed through the partial reflux unit to reflux glycols, and condensed water was distilled out of the reactor system.

When the acid value of the reaction mixture reached 4.5 mg KOH / g, heating was stopped, and the mixture was cooled to 120 ° C., and then fumaric acid 216
9g was charged. The temperature was started again, and the dehydration condensation reaction was carried out while taking care that the reaction temperature did not exceed 220 ° C.
After obtaining 5000 g of unsaturated polyester having 4.5 mg KOH / g and a hydroxyl value of 151.6 mg KOH / g, the mixture was cooled to 170 ° C., and 1.5 g of hydroquinone was added and mixed well.

Dissolve part of this unsaturated polyester in styrene,
An unsaturated polyester resin (A) containing 35% styrene was obtained.

Synthesis Example 2 Synthesis of unsaturated polyester and preparation of unsaturated polyester resin (b) In the same reactor as in Synthesis Example 1, 989 g of isophthalic acid, 1751 g of neopentyl glycol, 1044 g of ethylene glycol, and 2073 g of fumaric acid were charged. To produce an unsaturated polyester having an acid value of 2.3 mg KOH / g and a hydroxyl value of 232.3 mg KOH / g, and then dissolving with styrene to obtain an unsaturated polyester resin containing 35% styrene (b). .

Synthesis Example 3 Synthesis of unsaturated epoxy ester resin (c) 700 g of DEN 438 (a product of Dow Chemical Co., Novolak type epoxy resin, epoxy equivalent = 179), 340 g of methacrylic acid, styrene in a three-necked reactor equipped with a reflux condenser 693g,
2.08 g of triethylamine and 0.4 g of hydroquinone were charged and heated with stirring to 120 ° C.
The reaction was continued up to H / g to obtain an unsaturated epoxy ester resin (C).

The properties of the unsaturated polyester resins (a) and (b) and the unsaturated epoxy ester resin (c) are shown in Table 1.

Example 1 Unsaturated polyester resin obtained in Synthesis Example 1 (a) 8.
5 kg, a mixture of 0.5 kg of the unsaturated epoxy ester resin (c) obtained in Synthesis Example 3 and 1.0 kg of methyl methacrylate, 10 g of di-n-butyltin dilaurate as a urethanization catalyst, and 6% as a radical reaction accelerator -Add 80 g of cobalt naphthenate and place in the A side feed tank of the RIM machine. ISONATE143L (MD
4,4-diphenylmethane diisocyanate manufactured by Kasei Co., Ltd .;
(NCO equivalent = 143) To 10 kg, 200 g of t-butyl peroctoate is added as a radical reaction catalyst, and the mixture is placed in a B-side raw material tank of a RIM machine. When the mixing ratio of the A side and the B side is calculated so that the isocyanate group in the B side tank becomes 0.93 mole times the hydroxyl group in the A side tank, A side / B side = 4.27
It becomes 5 [g / g]. The injection speed (flow rate) of each of the A side and the B side was determined so as to achieve this ratio. Using the RIM machine with the conditions set as above, inject into the polycup for 1 second, and set the injection end time to 0 o'clock,
c Change in viscosity was measured with a rheometer (RM-1 manufactured by Shimadzu Corporation). As a result, the viscosities after 10 seconds and 60 seconds were 25 cps and 100 cps, respectively. The resin of this formulation had a very low viscosity for 60 seconds from the very beginning.

Next, a mold having a cavity size of 400 × 500 × 3 [mm] and having a fan gate on one short side of the rectangle and overflowing from the other short side when resin is injected is heated to 60 ° C.
Fill the continuous strand mat, close the mold vertically, inject it from below using the RIM machine prepared as above until the resin overflows from the top, close the mold for 2 minutes, then close the mold To remove the mold to obtain a fiber-reinforced thermosetting resin molded product. Glass content 42wt
%, 56% by weight, and 69% by weight, as a result, the impregnating property of the resin into the glass fiber was good and a completely filled one was obtained.

Examples 2 to 4 Except that the type and amount of the active hydrogen compound (A) in the A-side tank, the amount of methyl methacrylate, the amount of styrene, and the mixing ratio of A-side and B-side were changed as shown in Table 2. Was evaluated for the change in viscosity of the resin after mixing, the glass content, and the moldability in the same manner as in Example 1. The obtained evaluation results are shown in Table 2 together with Example 1.

Comparative Examples 1 to 6 Except that the type and amount of the active hydrogen compound (A) in the A side tank, the amount of methyl methacrylate, and the mixing ratio of the A side and the B side were changed as shown in Tables 3 and 4 Was evaluated for the change in viscosity of the resin after mixing, the glass content, and the moldability in the same manner as in Example 1. Tables 3 and 4 also show the obtained evaluation results. In all of Comparative Examples 1 to 6, the viscosity increased significantly after mixing, and the glass content during molding was 56%.
When it is higher than wt%, the back pressure becomes extremely high, and resin leaks from the mounting part between the mixing head and the mold of the RIM machine,
A completely filled molded article was not obtained.

Continuation of the front page (72) Inventor Hiroka Tanaka 5-6-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture, Japan Polymer Research Laboratory Mitsubishi Gas Chemical Co., Ltd. (56) References JP-A-1-131230 (JP, A) JP-A-2-84417 (JP, A) JP-A-61-209219 (JP, A) JP-A-57-139 (JP, A) JP-A-56-161418 (JP, A) JP-A-49-4798 (JP JP, A) JP-A-63-142018 (JP, A) JP-A-49-4799 (JP, A) JP-A-55-118912 (JP, A) JP-A-56-10424 (JP, A) JP-A-59-219324 (JP, A) JP-A-56-151718 (JP, A) Special table 58-501508 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 18 / 00-18/87 C08L 75/00-75/16 C08G 63/52-63/58 C08L 67/06-67/07 C08F 290/06 C08F 290/14 C08F 299/06

Claims (4)

(57) [Claims] 1. A fiber obtained by reaction injection molding a raw material component containing an active hydrogen compound (A) and a polymerizable vinyl monomer (B) and a raw material component containing a polyisocyanate compound (C) into a fiber (D). In the method for producing a reinforced thermosetting resin molded product, (A) is an unsaturated dicarboxylic acid or an acid anhydride thereof.
Unsaturated polyester having a hydroxyl value of 110 to 280 mgKOH / g and an acid value of 5 mgKOH / g or less obtained from a dicarboxylic acid or an acid anhydride thereof containing 40 to 100 mol% and a polyhydric alcohol having a primary hydroxyl group ( to a _1), an epoxy equivalent of having at least one epoxy group in the molecule
Selected from the group consisting of unsaturated epoxy esters (a ₂ ) obtained from 70 to 200 epoxy compounds and a polymerizable unsaturated monobasic acid, and acrylic compounds (a ₃ ) having an acryloyl group and a hydroxyl group in the molecule. An active hydrogen compound comprising at least one compound, wherein the ratio of a ₁ , a ₂ , and a ₃ is (a ₂ + a ₃ ) / (a ₁ + a ₂ + a ₃ ) × 100 = 1 to 15 wt%. (B) is a polymerizable vinyl monomer containing 5 to 40% by weight of methyl methacrylate, (C) is a terminal group having A liquid polyisocyanate compound having a viscosity at 25 ° C. of 10 to 2000 cps, and the following conditions (i) and (i)
i) (iii) (i) (B) is 20 to 50 with respect to the total amount of (A) and (B).
wt%, (ii) the isocyanate group of (C) is 0.75-1.2 mole times the hydroxyl group of (A), and (iii) (D) is the sum of (A), (B), (C) and (D). A method for producing a fiber-reinforced thermosetting resin molded product, which satisfies 30 to 75 wt% based on the amount. 2. An unsaturated dicarboxylic acid or its anhydride.
Unsaturated polyester having a hydroxyl value of 110 to 280 mgKOH / g and an acid value of 5 mgKOH / g or less obtained from a dicarboxylic acid or an acid anhydride thereof containing 40 to 100 mol% and a polyhydric alcohol having a primary hydroxyl group ( to a _1), an epoxy equivalent of having at least one epoxy group in the molecule
Selected from the group consisting of unsaturated epoxy esters (a ₂ ) obtained from 70 to 200 epoxy compounds and a polymerizable unsaturated monobasic acid, and acrylic compounds (a ₃ ) having an acryloyl group and a hydroxyl group in the molecule. At least one compound is blended, and the ratio of a ₁ , a ₂ , a ₃ is (a ₂ + a ₃ ) / (a ₁ + a ₂ + a ₃ ) × 100 = 1 to 15 wt% of an active hydrogen compound ( The raw material for molding a fiber-reinforced thermosetting resin which is A). 3. An unsaturated dicarboxylic acid or its anhydride.
Unsaturated polyester having a hydroxyl value of 110 to 280 mgKOH / g and an acid value of 5 mgKOH / g or less obtained from a dicarboxylic acid or an acid anhydride thereof containing 40 to 100 mol% and a polyhydric alcohol having a primary hydroxyl group ( to a _1), an epoxy equivalent of having at least one epoxy group in the molecule
Selected from the group consisting of unsaturated epoxy esters (a ₂ ) obtained from 70 to 200 epoxy compounds and a polymerizable unsaturated monobasic acid, and acrylic compounds (a ₃ ) having an acryloyl group and a hydroxyl group in the molecule. At least one compound is blended, and the ratio of a ₁ , a ₂ , a ₃ is (a ₂ + a ₃ ) / (a ₁ + a ₂ + a ₃ ) × 100 = 1 to 15 wt% of an active hydrogen compound ( A raw material for molding a fiber-reinforced thermosetting resin containing A) and a polymerizable vinyl monomer (B) containing 5 to 40% by weight of methyl methacrylate. 4. An unsaturated dicarboxylic acid or its anhydride.
Unsaturated polyester having a hydroxyl value of 110 to 280 mgKOH / g and an acid value of 5 mgKOH / g or less obtained from a dicarboxylic acid or an acid anhydride thereof containing 40 to 100 mol% and a polyhydric alcohol having a primary hydroxyl group ( to a _1), an epoxy equivalent of having at least one epoxy group in the molecule
Selected from the group consisting of unsaturated epoxy esters (a ₂ ) obtained from 70 to 200 epoxy compounds and a polymerizable unsaturated monobasic acid, and acrylic compounds (a ₃ ) having an acryloyl group and a hydroxyl group in the molecule. At least one compound is blended, and the ratio of a ₁ , a ₂ , a ₃ is (a ₂ + a ₃ ) / (a ₁ + a ₂ + a ₃ ) × 100 = 1 to 15 wt% of an active hydrogen compound ( A) and a raw material component containing a polymerizable vinyl monomer (B) containing 5 to 40% by weight of methyl methacrylate; And a raw material component containing a liquid polyisocyanate compound (C) having a viscosity at 25 ° C. of 10 to 2,000 cps.